Objective To explore the extraction and purification process and antioxidant activity of mango kernel polyphenols.Methods The extraction process of mango kernel crude polyphenols is optimized by the orthogonal experiment. Mango kernel polyphenol extract is further separated and purified by the macroporous adsorption resin. Meanwhile, the antioxidant activities of mango kernel polyphenols before and after purification are analyzed with Vc as the control.Results The optimal process extraction for mango kernel polyphenols is a solid-liquid ratio of 1∶40 (g/mL), 50% ethanol, an extraction temperature of 60 ℃, and an extraction time of 70 min. Under these conditions, the polyphenol yield is 9.93 mg/g. The LX-17 resin has the best adsorption-desorption effect, with a static adsorption and desorption equilibrium time of 2.5 h. Dynamic adsorption-desorption conditions are as follows: sample solution with a concentration of 300 μg/mL, a volume of 40 mL, a flow rate of 3 mL/min, and elution with 50% ethanol, a volume of 320 mL, and a flow rate of 3 mL/min. Under these conditions, the mango kernel polyphenol purity is increased from 9.93 mg/g to 35.68 mg/g. In vitro reducing power of mango kernel polyphenols on DPPH, ABTS, OH, and O2- free radicals, as well as Fe³⁺ is significantly increased after purification, and the IC₅₀ is 19.25, 0.02, 106.90, 464.00 μg/mL, respectively.Conclusion The mango kernel polyphenols are ideal in antioxidant activity.